Bisphenol A (BPA)-based phenolic epoxy coatings can be used to protect steel and aluminum food/beverage cans from corrosion. Overtime, BPA may be released into the food/beverage. There may be health concerns over the release.
Non-can steel structures exposed to corrosive conditions for extended period of time have been cathodically protected. Typically, the potential of the steel surface may be polarized (pushed) more negative until the surface has a uniform potential. At that stage, the driving force for the corrosion reaction may be reduced or halted. An impressed current cathodic protection system may protect steel by converting alternating current (AC) to direct current (DC). For example, a pipeline protection system may include an AC power rectifier with a maximum rated DC output of between 10 and 50 amperes and 50 volts. The positive DC output terminal may be connected via cables to an array of anodes (often inert graphite) buried in the ground (the anode grounded). For many applications, the anodes are installed in a 60 m (200 foot) deep, 25 cm (10-inch) diameter vertical hole and backfilled with conductive coke.